我有一个大型数据集，专门收录了生物学期刊，由不同的人长期组成。因此，数据不在单一格式中。例如，在“作者”列中，我可以找到John Smith、Smith John、Smith J等等，但这是同一个人。我甚至不能执行最简单的操作。例如，我无法确定哪些作者写了最多的文章。
是否有一种方法在R中确定不同名称中大多数符号是否相同，并将其视为相同元素？
2个回答
11
有一些软件包可以帮助你完成这个任务，其中一些在评论中列出。但是，如果你不想使用这些软件包，我会尝试写一些 R 代码来帮助你。该代码将把“John Smith”与“J Smith”、“John Smith”、“Smith John”、“John S”匹配。与此同时，它不会匹配像“John Sally”这样的内容。
# generate some random names
names = c(
"John Smith",
"Wigberht Ernust",
"Samir Henning",
"Everette Arron",
"Erik Conor",
"Smith J",
"Smith John",
"John S",
"John Sally"
);
# split those names and get all ways to write that name
split_names = lapply(
X = names,
FUN = function(x){
print(x);
# split by a space
c_split = unlist(x = strsplit(x = x, split = " "));
# get both combinations of c_split to compensate for order
c_splits = list(c_split, rev(x = c_split));
# return c_splits
c_splits;
}
)
# suppose we're looking for John Smith
search_for = "John Smith";
# split it by " " and then find all ways to write that name
search_for_split = unlist(x = strsplit(x = x, split = " "));
search_for_split = list(search_for_split, rev(x = search_for_split));
# initialise a vector containing if search_for was matched in names
match_statuses = c();
# for each name that's been split
for(i in 1:length(x = names)){
# the match status for the current name
match_status = FALSE;
# the current split name
c_split_name = split_names[[i]];
# for each element in search_for_split
for(j in 1:length(x = search_for_split)){
# the current combination of name
c_search_for_split_names = search_for_split[[j]];
# for each element in c_split_name
for(k in 1:length(x = c_split_name)){
# the current combination of current split name
c_c_split_name = c_split_name[[k]];
# if there's a match, or the length of grep (a pattern finding function is
# greater than zero)
if(
# is c_search_for_split_names first element in c_c_split_name first
# element
length(
x = grep(
pattern = c_search_for_split_names[1],
x = c_c_split_name[1]
)
) > 0 &&
# is c_search_for_split_names second element in c_c_split_name second
# element
length(
x = grep(
pattern = c_search_for_split_names[2],
x = c_c_split_name[2]
)
) > 0 ||
# or, is c_c_split_name first element in c_search_for_split_names first
# element
length(
x = grep(
pattern = c_c_split_name[1],
x = c_search_for_split_names[1]
)
) > 0 &&
# is c_c_split_name second element in c_search_for_split_names second
# element
length(
x = grep(
pattern = c_c_split_name[2],
x = c_search_for_split_names[2]
)
) > 0
){
# if this is the case, update match status to TRUE
match_status = TRUE;
} else {
# otherwise, don't update match status
}
}
}
# append match_status to the match_statuses list
match_statuses = c(match_statuses, match_status);
}
search_for;
[1] "John Smith"
cbind(names, match_statuses);
names match_statuses
[1,] "John Smith" "TRUE"
[2,] "Wigberht Ernust" "FALSE"
[3,] "Samir Henning" "FALSE"
[4,] "Everette Arron" "FALSE"
[5,] "Erik Conor" "FALSE"
[6,] "Smith J" "TRUE"
[7,] "Smith John" "TRUE"
[8,] "John S" "TRUE"
[9,] "John Sally" "FALSE"
希望这段代码能成为一个起点，你可能需要调整它以适应任意长度的名称。
一些注意事项：
- R中的for循环速度较慢。如果你处理大量名称，请查阅Rcpp。 - 你可能希望将其包装在一个函数中。然后，你可以通过调整search_for来为不同的名称应用此函数。 - 这个示例存在时间复杂性问题，根据你的数据大小，你可能需要重新设计它。
- Joshua Daly
1
编辑：
search_for_split = unlist(x = strsplit(x = search_for, split = " ")); - Sharif Amlani5
这篇文章是在@joshua-daly的优秀回答基础上进行扩展，以实现两个有用的目标。
（1）查找由n>2个单词组成的名称的排列组合（例如罗伯特·艾伦·齐默曼，又名博伯·迪伦）。
（2）执行在不涉及所有记录名称的情况下定义的搜索（例如博伯·迪伦）。
（1）查找由n>2个单词组成的名称的排列组合（例如罗伯特·艾伦·齐默曼，又名博伯·迪伦）。
（2）执行在不涉及所有记录名称的情况下定义的搜索（例如博伯·迪伦）。
library(gtools)
x <- c("Yoda","speaks","thus")
permutations(n=3, r=3, v=x, repeats.allowed = FALSE) # n=num.elems r=num.times v=x
# generate some random names
names <- c(
"John Smith",
"Robert Allen Zimmerman (Bob Dylan)",
"Everette Camille Arron",
"Valentina Riquelme Molina",
"Smith J",
"Smith John",
"John S",
"John Sally"
);
# drop parentheses, if any
names <- gsub("[(|)]", "", names)
# split those names and get all ways to write that name into a list of same length
split_names <- lapply(
X = gsub("[(|)]", "", names),
FUN = function(x){
print(x);
# split by a space
c_split = unlist(x = strsplit(x = x, split = " "));
# get all permutations of c_split to compensate for order
n <- r <- length(c_split)
c_splits <- list(permutations(n=n, r=r, v=c_split, repeats.allowed = FALSE))
# return c_splits
c_splits;
}
)
split_names
# suppose we're looking for this name
search_for <- "Bob Dylan";
# split it by " " and then find all ways to write that name
search_for_split <- unlist(x = strsplit(x = search_for, split = " "));
# permutations over search_for_split seem redundant
# initialize a vector containing if search_for was matched in names
match_statuses <- c();
# for each name that's been split
for(i in 1:length(names)){
# the match status for the current name
match_status <- FALSE;
# the current split name
c_split_name <- as.data.frame(split_names[[i]]);
# for each element in c_split_name
for(j in 1:nrow(c_split_name)){
# the current permutation of current split name
c_c_split_name <- as.matrix(c_split_name[j,]);
# will receive hits in name's words, one by one, in sequence
hits <- rep(0, 20) # length 20 should always be above max number of words in names
# for each element in search_for_split
for(k in 1:length(search_for_split)){
# the current permutation of name
c_search_for_split <- search_for_split[[k]];
# L first hits will receive hit counts
L <- min(ncol(c_c_split_name), length(search_for_split));
# will match as many words as the shortest current pair of names
for(l in 1:L){
# if there's a match, the length of grep is greater than zero
if(
# is c_search_for_split in c_c_split_name's lth element
length(
grep(
pattern = c_search_for_split,
x = as.character(c_c_split_name[l])
)
) > 0 ||
# or, is c_c_split_name's lth element in c_search_for_split
length(
grep(
pattern = c_c_split_name[l],
x = c_search_for_split
)
) > 0
# if this is the case, record a hit
){
hits[l] <- 1;
} else {
# otherwise, don't update hit
}
}
}
# take L first elements
hits <- hits[1:L]
# if hits vector has all ones for this permutation, update match status to TRUE
if(
sum(hits)/length(hits)==1 # <- can/should be made more flexible (agrep, or sum/length<1)
){
match_status <- TRUE;
} else {
# otherwise, don't update match status
}
}
# append match_status to the match_statuses list
match_statuses <- c(match_statuses, match_status);
}
search_for;
cbind(names, match_statuses);
- emagar
网页内容由stack overflow 提供, 点击上面的可以查看英文原文，
原文链接
原文链接
agrep(近似字符串匹配) https://stat.ethz.ch/R-manual/R-devel/library/base/html/agrep.html - James KingRecordLinkage包可能会有所帮助。另外，我记得在这个之前的问题上有一些建议/链接。 - Richard Herron